Question

The heat capacity of a bomb calorimeter was determined by burning 6.79 g of methane (energy of combustion = -802 kJ/mol CH4) in the bomb. The temperature changed by 15.7°C. (a) What is the heat capacity of the bomb?

Answer 1

The heat capacity of the bomb calorimeter is found to be -21.61 kJ/°C, which indicates that it absorbs 21.61 kJ of heat for each degree Celsius temperature increase resulting from the combustion of a substance within it.

Step-by-step explanation:

To determine the heat capacity of the bomb calorimeter, we will use the provided information about the combustion of methane: the burning of 6.79 g of methane, a temperature change of 15.7°C, and an energy of combustion being -802 kJ/mol CH4. First, we calculate the moles of methane combusted using its molar mass (approximately 16.04 g/mol).

Moles of methane = 6.79 g / 16.04 g/mol = 0.423 mol

Next, we calculate the total heat released during the combustion:

Total heat (q) = -802 kJ/mol × 0.423 mol = -339.2 kJ

Now, we use the formula q = C×ΔT to find the heat capacity of the bomb where q is the heat released, C is the heat capacity, and ΔT is the temperature change. Solving for C:

C = q /ΔT = -339.2 kJ / 15.7°C = -21.61 kJ/°C

The heat capacity of the bomb calorimeter is -21.61 kJ/°C, which means that for every degree Celsius the temperature rises, the calorimeter absorbs 21.61 kJ of heat.

Answer 2

The answer to your question is: Cp = 7.52 kJ/g°C

Step-by-step explanation:

Data

Cp = ?

mass = 6.79 g

Energy = -802 kJ/mol CH₄

ΔT = 15.7°C

Formula

Q = mCpΔT

Solve for Cp

`Cp = (Q)/(mΔT)`

Process

- Convert energy to J

-802kJ/mol = - 802 000 J/mol

- Calculate heat capacity

`Cp = (802 000)/((6.79)(15.7))`

Cp = 7523 J/ g°C or

Cp = 7.52 kJ/g°C